index.js

import { validateJwt } from "https://deno.land/x/djwt/validate.ts";
import { makeJwt, setExpiration } from "https://deno.land/x/djwt/create.ts";
import { Application, Router } from "https://deno.land/x/oak/mod.ts";

const expirationMinute = 10;

const key = "dummy_key"

const getTokenExpirationAsMilliseconds = () => {
    return new Date().getTime() + expirationMinute * 60 * 1000;
}

const payload = {
    iss: "dummy_issuer",
    exp: setExpiration(getTokenExpirationAsMilliseconds()),
}

const header = {
    alg: "HS256",
    typ: "JWT",
}

const generateToken = () => {
    return makeJwt({ key, header, payload })
}

const validateToken = (token) => {
    return validateJwt(token, key, { isThrowing: false });
}

const router = new Router();

const app = new Application();

router
    .get("/generate", (context) => {
        context.response.body = { token: generateToken() };
    })
    .post("/validate", async (context) => {
        const { token } = (await context.request.body(true)).value;
        context.response.body = await validateToken(token) ? { isValid: true } : { isValid: false };
    });

app.use(router.routes());
app.use(router.allowedMethods());
await app.listen({ port: 8080 });